Director of Central Intelligence Agency John Brennan takes questions from reporters during a press conference at CIA headquarters in Langley, Virginia, December 11, 2014. The head of the Central Intelligence Agency acknowledged Thursday some agency interrogators used 'abhorrent' unauthorized techniques in questioning terrorism suspects after the 9/11 attacks. CIA director John Brennan said there was no way to determine whether the methods used produced useful intelligence, but he strongly denied the CIA misled the public. AFP PHOTO/JIM WATSON (Photo credit should read JIM WATSON/AFP/Getty Images)

WASHINGTON -- Central Intelligence Agency Director John Brennan approved his agency’s search of a walled-off computer network being used by the Senate Intelligence Committee to construct a report on the agency’s torture program, a CIA Accountability Review Board has found.

Despite Brennan’s direct involvement, though, the board has determined that neither he nor his subordinates acted improperly when agency employees sifted through certain emails and databases of the supposedly off-limits network designated for the Senate committee. Instead, the board suggests that Senate investigators may have been the ones who violated agreed-upon standards by obtaining the secret, internal CIA document that prompted the agency’s search.

The panel’s official conclusions, released Wednesday, add a further twist to the remarkable feud between the Senate and the CIA that has unfolded around former Senate Intelligence Committee chair Dianne Feinstein’s (D-Calif.) behemoth report on the CIA's post-9/11 torture program. The feud -- which has involved allegations of spying, a classified document secretly removed from a secure CIA facility, and competing criminal accusations -- resulted in a borderline constitutional crisis that, more than a year later, remains unresolved.

Many observers believed that the Accountability Review Board would serve as the CIA’s official mea culpa for conducting a security review of the Senate committee’s network, an allegation that was confirmed by the CIA’s Office of the Inspector General in July 2014. After the IG determined that five CIA employees had, in fact, improperly accessed certain corners of the restricted Senate computer drive, the agency tasked the review board with evaluating that incriminating conclusion.

“Director Brennan apologized for these actions and submitted the [Inspector General] report to an accountability board,” Feinstein said after the commissioning of the review board, indicating the hope on behalf of lawmakers that the panel would lead the CIA to reckon with its actions. “These are positive first steps.”

But instead, the board has backtracked on the spies’ prior concession that the snooping was improper. Despite hopes that the review would bring an end to the dispute, the ARB’s controversial conclusions will likely only reopen the wound.

The agency on Wednesday also released a declassified version of the Inspector General report, whose release has been fiercely contested for months. A one-page summary of the inquiry was first made available in July, and Democratic lawmakers have been demanding its complete public release ever since.

The ARB investigation was led by Evan Bayh, a former Democratic senator from Indiana. The board also included former Obama White House counsel Bob Bauer and three current CIA officers.

Brennan’s confirmed involvement in the computer search answers questions that, up to this point, the CIA has hedged on for months. The spy chief has refused for the past year to tell lawmakers who authorized the search, and has staunchly rejected their requests for answers after the Inspector General determined that the computer trespasses were improper.

According to the accountability board, the security review itself consisted of three different “looks” into the Senate hard drive. The first, which took place on Jan. 9 and 10, 2014, was a provisional examination to investigate suspicions that Senate staffers possessed a secret CIA document colloquially known as the “Panetta Review” on their side of a shared computer network. After determining that staffers did have the internal agency document, CIA officials sought the advice of agency leadership. At that time, Brennan ordered the spies to determine whether the document had been accessed or printed by staff in a second “look,” which took place on Jan. 10.

On Jan. 14, following this second search, Brennan, concerned about potential ramifications, ordered the agency investigators -- who were the five employees identified by the Inspector General-- to stand down until he discussed the matter with Feinstein at an emergency meeting the following day. But even after those five CIA employees stopped their probe, the CIA’s Office of Security continued digging separately, and ultimately accessed five Senate staff emails before finally being called off.

“At a minimum, they had an ongoing obligation to tend to the security of the network,” said a source familiar with the board’s deliberations, adding that the agency had to be sure there was evidence of wrongdoing before it accused the Senate of pilfering the document.

The source added that the ARB believes Brennan did not know the extent of intrusion that was required into the Senate drive to answer his questions.

The accountability board concludes that the snooping wasn’t improper and didn’t violate the agreement established ahead of time by then-Senate Intelligence Committee Chairwoman Feinstein and then-CIA Director Leon Panetta.

The terms of that agreement, the board claims, only protected the work product of intelligence committee investigators, not databases and files of shared documents that the CIA provided for the committee’s use. While the accessing of emails did violate those parameters, the board says, the Office of Security acted reasonably because it had a responsibility to preserve the security of the system.

Furthermore, the ARB says committee investigators knew that the agency occasionally entered and searched the Senate side of the shared computer system -- known as “RDINet” -- for maintenance and security checks.

“[Senate Intelligence Committee] staffers were or should have been aware of, CIA’s [redacted] monitoring of RDINet for security purposes,” the report says. “In fact, CIA had previously accessed [redacted] collected from the [Senate] side of RDINet when security concerns arose.”

The CIA's security review was a result of concern among agency personnel that Feinstein’s investigators had somehow obtained access to off-limits CIA documents known as the Panetta Review. Feinstein alleges that the CIA’s review violated the constitutional separation of powers, and may have been a breach of the law.

The Accountability Board, however, sees no such transgressions. In fact, it says, the trespass wasn’t only proper, but also necessary. The agency had a duty to snoop through Senate files to discover whether the Panetta Review had found its way into the hands of Feinstein’s staff.

Led by CIA Inspector General David Buckley, that investigation determined that the five agency employees acted improperly when they combed through the off-limits Senate drive, and also that the CIA subsequently lied about its actions.

The ARB refutes those claims, and in fact accuses the IG of flubbing its inquiry. Buckley’s report, according to the accountability board, missed key details and fundamentally erred in declaring that the CIA did not have the right to conduct the invasive security inquiry.

The Accountability Review Board also purports to answer a question that, until now, no other inquiry has been able to tackle: how, exactly, staff came to possess the Panetta Review, an internal CIA document that supposedly undercuts the agency's official response to the torture study.

The CIA has accused Senate staff of improperly accessing CIA networks in order to obtain the Panetta Review. Feinstein has vehemently denied that claim, and says her staff stumbled upon the document in the course of a routine search.

According to Feinstein, the document was somehow provided by the CIA to the committee, possibly by accident. Alternatively, she suggests, a whistleblower may have slipped the Panetta Review somewhere they knew the Senate investigators would find it.

But the ARB’s new findings determine that the CIA didn’t provide the document to investigators either by accident or through a whistleblower. That suggests the alternate explanation that the spies have been pushing: Senate staffers intruded into restricted CIA networks to obtain the Panetta Review, which they should have known they weren’t entitled to.

According to new details revealed in the accountability board’s investigation, on Nov. 9, 2010, one Senate staffer came upon a collection of internal summaries about the CIA’s torture program, summaries that have now come to be called the Panetta Review. The staffer accessed roughly 166 Panetta Review files. Later, the staffer printed out the files and also transferred them to the user drives of four Senate colleagues.

It is unclear how the Senate investigator originally accessed the files, though the board’s report says the staffer “directly navigated” the folder path containing the secret summaries. Whether that navigation was possible due to a hole in a CIA firewall, a technological glitch or something else remains uncertain.

The ARB report takes a number of additional hits at Senate investigators, pointing to two previously unknown incidents that occurred during the torture investigation. On two separate occasions, the report writes, Senate investigators significantly violated protocol. One instance was so serious, the board says, that the matter was referred to the CIA’s counterespionage group, and the Senate staffer in question was pulled from the torture report team.

The board also questions the validity of the Senate's torture report, a summary of which was released in December. The Senate committee, the ARB suggests, may have used the Panetta Review in putting together its torture report, even though the CIA has questioned whether the document is credible as evidence material. According to the CIA, the Panetta Review summaries were not an objective, internal analysis of the torture program. Rather, the agency has said the summaries’ purpose was to construct the worst-case conclusions that could be drawn from the records being given to Senate investigators -- a sort of preemptive defense. Therefore, the CIA says, the summaries do not reflect objective critiques of the torture program.

Yet Senate investigators, the ARB report has found, may have based their behemoth torture study on the faulty summaries rather than independent analysis of primary documents.

The intelligence committee has staunchly denied this claim, and continues to stand behind the accuracy and comprehensiveness of the study. Feinstein has said that her staff did not rely on the Panetta Review when conducting the investigation.

The ARB also recommended several systemic changes to matters that involve the CIA and Congress, such as suggesting that a clearer set of standards be defined whenever a shared computer network is used in the course of oversight, and that the agency's Office of Congressional Affairs be involved throughout any future matters that could potentially cause controversy.

The core of the dispute, said the source familiar with the board review, was the lack of clear agreement over how the shared system was to be utilized by the two sides, and how a security violation was to be handled if the CIA identified one.

“The root of the problem was the absence of clear protocol," the source said.

Bayh and Bauer briefed both Feinstein and Senate Intelligence Committee chair Richard Burr (R-N.C.) on the report this morning, Bayh said in a statement Wednesday.

The dispute over the Panetta Review has been a long, complicated saga that, despite a number of investigations, continues to cloud the critical relationship between the CIA and its chief congressional overseers.

As part of Feinstein’s massive study on the torture program, the CIA provided millions of documents, cables and records to her staff at an offsite agency facility in northern Virginia, starting in 2009.

In 2013, after the CIA released its official response to the Senate torture investigation, Feinstein’s staff began to notice discrepancies between the agency’s official position and the internal critiques of the torture program they had found in the Panetta Review. Realizing the importance of the document, staffers slipped the classified Panetta Review out of the secure CIA facility back to their secure office spaces in the Hart Senate Office building.

The staff’s actions remained a secret, until the CIA realized, following official committee requests for the Panetta Review, that Feinstein and her staff had somehow gotten their hands on the summaries. The ARB determines that a CIA employee overheard a Senate investigator claiming to have seen “the real response” to the torture report, indicating to the employee that the staffer had obtained the Panetta Review.

The realization prompted the CIA's emergency security review of the computer system last January, in an attempt to find out how staff had obtained the document.

Feinstein, learning after the fact that the search had taken place, accused the CIA of violating the Constitution, setting off a firestorm between the agency and the halls of Congress.

The incident led to a flurry of investigations, including the CIA Inspector General’s report, which appeared -- until now -- to have resolved the issue in favor of Feinstein's version of events.

The path forward following the Accountability Review Board’s report is unclear. The findings invoked the rage of several Democratic lawmakers on the intelligence panel.

"Let me be clear: I continue to believe CIA’s actions constituted a violation of the constitutional separation of powers and unfortunately led to the CIA’s referral of unsubstantiated criminal charges to the Justice Department against committee staff," Feinstein said in a statement Wednesday. "I’m thankful that Director Brennan has apologized for these actions, but I’m disappointed that no one at the CIA will be held accountable. The decision was made to search committee computers, and someone should be found responsible for those actions."

In a separate statement, committee member Sen. Ron Wyden (D-Ore.) said, "It is incredible that no one at the CIA has been held accountable for this very clear violation of Constitutional principles. Director Brennan either needs to reprimand the individuals involved or take responsibility himself. So far he has done neither.

"At a time when the CIA appears incapable of policing itself, the intelligence community needs more external oversight, not less," Wyden added.

But having recently lost control of the Senate, the Democrats who are heavily invested in the matter will have a difficult time rallying support for congressional action. Burr, the intelligence panel's new chair, has long been uncomfortable about committee staffers accessing and removing the Panetta Review, and he is not likely to share his colleagues' dissatisfaction with the accountability board’s conclusions.

The ARB, having found no evidence of wrongdoing, does not recommend punishment for any CIA employee involved in the snooping. And it's unlikely that the Inspector General would revive any investigation. It seems the only remaining questions have to do with the gritty details of how, exactly, staff obtained the Panetta Review. And the Senate’s chief law enforcement office, the sergeant-at-arms, has already declined to explore that avenue due to the lack of original computer records.

Exactly one year ago Wednesday, Brennan was scrambling, desperately trying to determine how a sensitive, potentially explosive CIA document wound up in the hands of Senate investigators. And now, exactly one year later, the furious energy behind that feud may have finally -- albeit inconclusively -- been exhausted.

In this image from TV, U.S. President Barack Obama shakes hands with Cuban President Raul Castro at the FNB Stadium in Soweto, South Africa, in the rain for a memorial service for former South African President Nelson Mandela, Tuesday Dec. 10, 2013.